1. Field of the Invention
The present invention pertains to a method and system for treating crude oil and other heavy hydrocarbon sludges wherein a filler material, such as diatomaceous earth, is mixed with the sludge and the sludge is incinerated or otherwise oxidized in a rotary kiln or calciner-type apparatus to provide a friable hydrocarbon free solids substance which may be recycled for use with the sludge at the input to the process.
2. Background
Certain types of hydrocarbon sludges are difficult to process for disposal purposes, such as crude oil sludges resulting from refinery processes, tanker ballast treatment systems, oil spills and other sources of compositions of crude oil and solids. Many sludges of the aforementioned type have sufficient quantities of solids, such as earth materials, metal scale and other materials as to prevent their disposal by incineration through atomization in a combustion chamber. These sludges may originate from processes which do not justify elaborate capital equipment systems, but yet pose hazards to the environment which prohibit their direct disposal without treatment.
Our U.S. Pat. No. 4,747,961 issued May 31, 1988, and our U.S. Pat. No. 4,787,323, issued Nov. 29, 1988 and entitled "Treating Sludges and Soil Materials Contaminated with Hydrocarbons" are directed to methods and systems for handling hydrocarbon sludges which include both crude oil and more volatile hydrocarbons. The systems disclosed in the abovementioned applications are also more suitable for disposal of large quantities of sludge materials on a continuous basis.
Many crude oil sludges and similar heavy hydrocarbon sludge materials cannot be subjected to conventional incineration because such sludge processes form clinkers or substantial scale buildup in the incinerator apparatus, particularly when such sludges cannot be atomized in a combustion chamber. However, in accordance with the present invention, a process and system have been developed for handling crude oil sludges and other heavy hydrocarbon sludge materials which maintains the sludge material essentially free-flowing and provides a friable mixture which may be directly incinerated to produce gaseous combustion products and a friable solids mixture which may be easily handled and even recycled for use in the process.